The present invention relates to a motor and an actuator for driving the motor.
Various types of dampers and louvers are provided in automobile air conditioner ducts to change the flow of air. Dampers are generally driven by actuators, which are typically powered by electric motors. Japanese Unexamined Patent Publication No. 9-329215 describes an example of such an actuator.
The actuator described in the publication has a gear case incorporating a speed reducer. A stepper motor is attached externally to the gear case. After installing the motor on the gear case, a receptacle housing is secured to the gear case to cover the bearing of the motor. This prevents dust from entering the space between the shaft of the motor and the bearing.
Although the receptacle housing improves the dust-resistance of the prior art actuator, the housing adds to the number of parts and increases the number of assembling steps. This, in turn, increases the production cost.
Accordingly, it is an object of the present invention to provide a motor and an actuator driven by the motor that is manufactured from a less number of components and has an improved dust resistance.
To achieve the above object, the present invention provides a motor including a hollow yoke having an open end, a coupling member coupled to the yoke so as to cover the open end of the yoke, and a stator accommodated in the yoke. The stator has a receptacle. A rotor is received in the receptacle. The rotor has a first end and a second end. A first bearing is arranged on the coupling member or the stator to rotatably support the first end of the rotor. A second bearing is formed integrally with the yoke to rotatably support the second end of the rotor.
Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.